Cement for metallic filaments.



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5 I I I Q iv W 7 f? i UNITED STATES PATENT OFFICE.

KARL FABKAS, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO GUY V. WILLIAMS,

OF NEW YORK, N. Y.

CEMENT FOR METALLIC FILAMENTS.

1,044,15 Specification of Letters Patent. Patented Nov. 12, 1912. R0 Drawing. Application filed August 11, 1909. Serial No. 512,279.

To all whom it may concern: The tungstous oxid is re ared referabl 4 Be it known that I, KARL FARKAS, a citiin the following iiia nn r: Tungs iic anhy zen of the Kingdom of Hungary, and a drid 0 or tungstic acid YVO(()H) or resident of New York, in the county and the acid W'O,(OI-l) or the acidVV,O (OI-I) 5 State of New York, have invented certain are brought into contact with zinc and dinew and useful Improvements in Cement luted hydrochloric acid. By this reduction for Metallic Filaments, of which the {01- the solution first becomes blue by the formalowing is a specification. tion of tungsten entoxid W 0 then it This invention has reference to improvebecomes brown by the formation o f oxid of 10 ments in cement for metallic filaments by lower valency like the dioxid W0 This means of which same are secured or cecompound is washed an me an passed mented to the inner ends of the conducting through fine silk sieves. When thus preor leading-in wires of the incandescent elecpared some metalli e aluminum powder is tric lamp. mixed therewith, a'quantrtyaf'fiom 2 to 3% 15 It is the special object of my invention is sufficient. This, mixture is then rubbed to produce a novel cement by means of In -Q flggrgd tgg orllsodium silicate solution which the breaking 03 of the filaments near nt l a paste 01 celiient of proper consistency the cemented portion is reduced to a minihas been obtained. The cement thus premum. This cement is prepared essentially pared is now applied. The filaments to- 20 from inorganic, mineral substance and some gether with the connecting cement portions metal "peace? and a suitable binding ma- Mejia-dim a stove and then the cemented I terial. Accordingly this cement produces a portion a One is electrically heated in an perfect metallic connection between the meatmos here of h did eifwiifireb y' tlie tungtallic filament and the ends of the leading-in stous oxid is reduced to elementar tun 25 wires. When the cementing is finished sten. Now the stem with filamenfi 1's msuch metallic connection does not give off men into the lamp globe and the lamp any gases neither can it absorb same. Thus finished 1n the usual manner. During the the vacuum in the lamp is retained at its process of exhaustion no gases will be given normal height and can not be impaired off by this perfect metallic connection be- 30 even if such metallic connection would be cause such metallic connection can not abheated to a higher than the normal temsorb any gases as is the case with graphite perature usually produced therein during cement for carbon lamps. the operation of the lamp. The principal By the employment of this novel metallic component of the novel cement, i n oxid cement the breakage of the filaments near 35 in its lower valency of the elementary'gfil'ithe cement is reduced to a minimum wherestance'(if'whicli'the metallic filament itself by a great saving is effected. 'jfglgompggse d. During the process of niaiiii I claim as my invention:

facture such lower oxid is reduced and 1. As a new article of manufacture, a cetherefore a metallic connectid? f5 formed t for metallic filament consisting of 40 between the filament and the leading-in oxids of a low valency of a highly refrac- .wires. This connection, however, is sufiitory elementary substance in form of fine ciently large in comparison to the diameter powder, a small quantity of metallic alumiof the filament to offer but little resistance num powder, and suflicient liquid binder to to the electric current and therefore is not impart the pro-per consistency. 45 heated to an appreciable extent. 2. As a new article of manufacture, a

In carrying the invention into eifect I cement for metallic filaments composed of substantially proceed as follows: Assuming fine powder of oxids of a low valency of that tungsten filaments are to be cemented the highly refractory metal of which the then the cement is prepared from tun stous filament is made, a small quantity of metal- 50 oxid to which a small percentage of metallic aluminum powder, and sufiicient liquid 10 a uminum is added. Both are mlxe binder to impart the proper consistency.

oro 1 y and rubbed into some thinned 3. As a new article of manufacture, a tar other suitable binding materla as cement for tungsten filaments composed of for instance a solution of sodium silicate. "tuiigstiiiis oxids in form of fine powder, a

tungstous oxids in form of fine powder, from 2 to 3 per cent. of metallic aluminum powder, and sufficient solution of sodium silicate to impart the proper consistency.

Signed at New York, N. Y., this 10th day of August, 1909.

KARL FARKAS.

Witnesses:

LUDWIG K. Bonn, GUY V. WILLIAMS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

